Apparatus for X-ray photographing tubular steel castings



March 16, 1948. FORSSELL 2,437,688

APPARATUS FOR X-RAY PHOTOGRAPHING TUBULAR STEEL CAS TINGS Filed Jan. 12, 1945 Patented Mar. 16, 1948 APPARATUS FOR X-RAY PHOTOGRAPHING TUBULAR STEEL CASTINGS Eric G. Forssell, Kenmore, N. Y., assignor to W. H. Miner, Inc., Chicago, 111., a corporation of Delaware Application January 12, 1945, Serial No. 572,562

4 Claims.

This invention relates to improvements in apparatus for X-ray photographing tubular steel castings for detecting flaws in such castings.

One object of the invention is to provide an apparatus for X-ray photographing flaws in tubular steel castings comprising a rotary chuck or table on which the tubular steel casting is clamped. for rotation therewith, a source of X-rays radial to the axis of rotation of the table and tubular member, a photographic film holder telescoped within the tubular casting for holding a continuous film in close proximity to the inner face of the side walls of the casting, a lead screen between the tubular member and the source of X-rays, the screen having a lengthwise extending, narrow opening therethrough, permitting the free passage of X-rays, thereby confining the action to a relatively narrow field, and means for rotating the table, wherein the side of the film opposite to that being X-rayed is protected by a fixed screen member projecting into the tubular casting and the film holder therewithin and extending lengthwise thereof, the screening member being of a width to exclude all rays passing through the slot of the lead screen.

Other objects of the invention will more clearly appear from the description and claims hereinafter following.

In the drawing forming a part of this specification, Figure 1 is a side elevational view of my improved apparatus. Figure 2 is a front elevational view, looking from left to right in Figure 1. Figure 3 is a horizontal, longitudinal sectional view through the center of the tubular casting and film holder, corresponding substantially to the line 3-3 of Figure 1, showing the screening element in plan. a

As shown in the drawing, my improved apparatus comprises broadly a supporting frame A; a rotary table or chuck B; a slotted screen C; a hinged table D for supporting the screen; an elongated screening element E; and clamps F-F for fixing the casting to the table B.

The supporting frame A includes a horizontal platform ID, the front end portion of which only is shown in the drawing. The platform is mounted on suitable feet ll, only one of which is shown in Figure l of the drawing.

The rotary table or chuck B is in the form of a flat disclike plate having a rearwardly extending shaft 14 secured thereto, which is rotatably supported in a bearing element [2 carried by an upright standard [ion the platform Ill. The driving means for the shaft is not illustrated but it is such that the shaft I4 is rotated at rela- 2 tively slow speed. The driving means may be in the form of an electric motor and any well-known type of reduction gearing interposed between and connecting the motor to the shaft M.

The rotary table or chuck B carries the clamps F-F, which are disposed at opposite sides of the center of rotation of the table and are in the form of hooks having straight shank portions 15 extending through openings in the table B. The shanks Iii-I5 are threaded at their outer ends to receive clamping nuts l6. At their opposite ends, the clamps F-F are provided with angularly bent portions Il-l'l substantially at right angles to the shanks forming the hook members proper of said clamps. The clamps F-F are especially designed to securely mount the particular type of tubular casting l8 herein illustrated, namely, the casing of a railway friction draft gear of well-known design, on the table B. The well-known draft gear referred to comprises briefly the casing l8 and a spring resisted friction clutch slidable in the casing, which is of hexagonal, interior and exterior cross section. This type of casing is provided with the usual openings 19-! in the sides thereof. .In the present instance, these openings are used in clamping the casing 18 to the table B, the hook portions of the clamps F-F being engaged in these openings and the clamps locked to the table by the nuts IS.

The supporting table D for the screen C is in the form of an open rectangular frame having rearwardly extending arms 20-20 hinged at their rear ends to upright columns 2l-2l supported by the platform Ill. The table D is supported in horizontal position by arms 22-22 of the frame A, which extend forwardly from the columns 2l-2l, and are braced at their front ends by struts 23-23 extending from the platform ill, the table resting or being supported on upstanding portions 24-24 at the front ends of the arms 22-22.

The screen C, which is supported by the table or frame D, comprises a pair of laterally spaced, thick, lead plates 25-25 supported within the opening of the frame D by clamps 26-26. The plates 25-25 are arranged lengthwise of the axis of rotation of the draft gear casting l8 and the opening between these plates extends lengthwise of the latter, parallel to and in vertical alignment with its axis of rotation.

The X-ray apparatus employed with my improved mechanism is of well-known type and is indicated by 21. As shown in Figure 3,.the same is located above the screen C in verticalalignment with the axis of rotation of the draft gear tasting l8 and the opening of the screen.

A suitable film holder 28, which is in the form of a hollow, tubular member, comprising inner and outer tubular shells between which the film is held, is fitted within the open end of the casting [8.

The screening element E is in the form of a relatively thick lead bar projecting into the opening of the film holder 28 in close proximity to the upper side thereof. The bar E extends hori zontally and is supported by a detachable bracket 29 mounted on the platform I!) of the frame A. The bracket 29 includes a iaterallyinwardly' ex tending foot portion 33 at its lower end secured to the top of the platform by a bolt 31 The bar E is fixed to the upper endof'the bracket 29 by a bolt 32 extending through said bar and a laterally outwardly projecting flange 33" on'the' bracket.

The operationi'of -my'improved' apparatus-is as follows:- The tubular steelcasting; in this case, the hexagonal casting l8; to be-X-rayed; withthe film holder 2B"therewithin; is'mounted'on'th'e rotary table orchuck B, being secured'by' the clamps F'F.' The bracket 29* with the' lead screening bar E attached thereto is then fixed in position on the platform Hlwith'thebar'E'pro- J'ecting' into thefilm holder-28'; which is within the casting t8; The'table D, which hasbeen swung upwardlyduring the operation of clamping the casting to-the chuck'B;is thenlowered to the horizontal position shownimFigure-l." Power is then' applied-tothedriving shaft [4 to slowly rotate the same'and the chuck'B together with the casting Iilthereon; At the same'time, electric current'is supplied tothe X ray apparatus 21; thereby exposing; the" casting" It" and the photographic filn'r'in theholder 23 to the rays emanating from the; X ray apparatus In this connection, it is'p'ointed out'that the leadbar E properly"screens"that' portion of the photographic film"at"the"si de of the film'holder opposite to that exposed to thesource' orXf ray during rotation of'the tubular casting, thereby preventing marringof theex'posure which would otherwise occur by difiused rays' reaching this portion of the film; the 'barE beingofgreater width than theopeningof the screen C,'that is, of ample width to take care of any' diverging rays passing through said opening: H

I have herein shown and described what I now consider the pref erred" manner of' carrying out my invention, but the'same'is'merelyillustrative and 'I contemplateall changesand modifications that come within the' scope of the-claims appendedhereto:

I claim:

1. In an apparatus for producing ray photographs-of tubular'steel castings, the combination witha rotary'supporting' 'table'; of means for transmitting slow rotary motion to saidtable; means on said table; for" clamping atubular'steel casting thereon with its central-longitudinal axis inalignment with the axis ofrotationof the table; a-hollow'tubular photographic film-holder mounted within said casting" for rotation in unison therewith, said"holder-'fitting'within' the tubular casting and'having a photographic film arranged annularly therein: a screenof material impervious to X-rays parallel to the axis of rotation of-said table at one" side of the latter, said screen having an elongated aperture there: through, i the length of 'said aperture being parallel to said= axis of rotation} a-scre'en impervious 4 t to X-rays within said film holder, said second named screen being mounted on a fixed support and being of greater width than said aperture; and an X-ray tube remote from said table, said first named screen being introduced between the X-ray tube and the tubular casting on said table.

2. In an apparatus for producing 'X-ray photo graphs oftubular steel castings, the combination with a rotary supporting table; of means for transmitting slow rotary motion to said table; means-'on said table {or clamping a tubular steel casting'thereon with its central longitudinal axis in alignment with the axis of rotation of the table; ahollow tubular photographic film holder fittingwithijn': the tubular casting for rotation in unison" therewith and having a photographic filmarranged annularly therein; a screen of material impervious to X-rays parallel to the axis of'rotation of said table at one side of the latter, said screen having an elongated aperture therethrough, the length of said aperture being parallel 'to 'sai'd aids of-rotation; a fixed support; a second screenimp'erviousto-x rays fixed to said support and extendinginto thehollow portion of said film hol'derparallel to" said axis of rotation, said second named screen being of greater width than 'saidaperture; and X-ray tube remote from said table, said firstnamed screen being interposed between the X raytube and the tubular ca'stingonsaid. table.

3. Inan apparatus for' producing X ra'y' photographs of' tubular steel castings; the'combination with a rotary 'supporting table; of 'meansfor transr'nitting slow rotary motion to said' table; means 'on said table 'for clamp'in'g a tubularsteel casting thereon with its central longitudinal axis in alignment With} the axis oi rotation of the table; a hollow tubularphoto'g-raphic' min holder fitting within the"tubul'ar casting for rotation in unison therewith andhaving a 1 photographic film arranged annularly' therein a screenofmaterial impervious to X ra'ys parallel tothe axis of rotation of said table at one-si'deof the latter, said screen: havingan elongated aperture therethrough, the length of said aperture beingpaial lel to said axis'qof 'rotation z-a fixed support; an elongated screen impervious to X rays fixed to said support and extending into the h'olldwpor tionof said illrn holder paranertd said axis of rotation, saicl second 'named screen being of a width at least as great as the elo''rigat'ed aperture of said first named screen;- andan X-ray tube remote from said 'table, said first named screen being interposed between the X raytube and the' tubular toasting on said table.

4. In anapparatusfor producing X ray pliotm graphs of tubular steel castings, thecombination witha: tabl'e rotatable about a," horizontal axis; of means for transmitting-rotary motion toflsa'id table; means on said table 'f'oricl'a' mping a: tubular steel: casting there on with its central longitudi nal axis in alig nment'with the axi's of rotation of the tablepanf x-ray'tube suspendedabove said tubular casting-vertically above the axis of rotation thereoff a stationary'horizontal"soreen inter posed between said tubularsteel oastingand said X-ray tube; saidscreen being impervious to X rays and having-" an elongated'narrow opening therethrough',- said opening being j alignedflengthwise with said'axis'of rotation; an elongated stationary -hori'zbntalscreen ofgreater width than said? opening, said elongatedscreenbeing-mount ed'below said'firs't named screen in vertical alignment with the opening thereof; said second named screen 'extending'into-said t'ub'ular I cast- 6 ing; and a hollow tubular film holder mounted within said tubular casting for rotation in uni- UNITED STATES PATENTS son therewith, said film holder surrounding said Number Name Date Second named Screen- 1,704,477 Jacobson Mar. 5, 1929 ERIC FORSSELL- 5 2,281,931 Frank May 5, 1942 2,340,923 Boucher Feb. 8, 1944 REFERENCES CITED 2,386,658 Caspersz Oct. 9, 1945 The following references are of record in the file of this patent: 

